UKN Miraya Rose: My investor's ROI dilemma

Since January I've been eyeing UKN Miraya Rose, thinking about investment. Builder ne bola tha 5-6% rental yield easily aayega, but market checks say it's barely 3%. Iska resale market bhi utna liquid nahi lag raha, honestly. My parents keep saying check builder's track record properly. Anyone else faced this gap with their ROI expectations?